Grinding machine



A. MARKLE GRINDING MACHINE Feb. 17, 1959 9 Sheets-Sheet 1 Filed Dec. 13. 1954 (I; I 'II 1 h Bf" Aoau= MA'RKLE Feb. 17, 1959 A. MARKLE GRINDING MACHINE 9 Sheets-Sheet 2 Filed. Dec. 13, 1954 Inventor:

9 Sheets-Sheet 3 Filed Dec. 13, 1954 Inventor: ADOLF MARKLE B Feb. 17, 1959 A. MARKLE GRINDING MACHINE 9 Sheets-Sheet 4 Filed Dec. 15, 1954 fm emon A0014: MA'RKLE Feb. 17, 1959 A. MARKLE 2,8

GRINDING MACHINE Filed Dec. 15. 1954 9 Sheets-Sheet 5 Inventor:-

A DOLF "M R KL-E Feb. 17, 1959 A. M'ARKLE 2,873,557

/ GRINDING MACHINE Filed Dec. 13, 1954 9 Sheets-Sheet 6 Inventor? HDOLF WARM-5 Feb. 17, 1959 A. MARKLE GRINDING MACHINE 9 Sheets-Sheet 7 Filed Dec. 15, 1954 FIG. 12

P h w m n" S mm L 7 M r 4 u A 2% Av FebQ/l7, 1959 A. MARKLE 2,873,557

GRINDING MACHINE Filed Dec. 13, 1954 481 9 Sheets-Sheet 8 INVENTOR.

do! 37121- M Feb. 17, 1959 A. MARKLE 2,873,557

GRINDING MACHINE Filed Dec. 13, 1954 9 Sheets-Sheet 9 FIG. 14

INVENTOR.

United States Patent GRINDING MACHINE Adolf Markle Tubingen, Germany, a ssignor to Firma Montanwerke Walter Aktiengesellschaft, Tubingen, Germany Application December 13, 1954, Serial No. 474,761

16 Claims. (Cl. 51-33) The present invention relates to grinding machines, and

more particularly to a grinding machine for grinding an at least partly cur'vedface on a workpiece.

,It is known to grind a cutter along a clearance face composed of two straight face portions and a curved face portion connecting the two straight face portions. The

grinding wheel is guided along the straight and curved face portions, butthe ground surface is not perfect, and particularly the curved face portion is insufficiently ground since the grinding wheel moves only slowly along the curved surface portion.

It is the objectjof the present invention to overcome this disadvantage of the knowngrinding machines for grinding at least partly curved faces on cutters, and to provide a grinding machine which produces a smooth surface and perfect cutting edge on a cutter of the above describedtype. f r

1 i It is another object of the present invention to oscillate means so as to produce a perfectly ground surface.

With these objects in view, the present invention mainly consists in a grinding method which comprisesthe steps of moving a grinding means at a predetermined speed along an at least partly curved path whose shape corresponds to the shape of a face on the work piece engaged by the grinding. means and being ground by the same; and oscillating thegrinding means during movement along said path ,ata speed substantially greater than the speed along said path.

..The apparatus of the present invention mainly com prises, in combination, a support for a workpicce having an at least partly curved face, a grinding meansfor grinding the face of the workpiece, movable supporting means supporting the grinding means, guiding means for guiding the movable supporting means along an at least partly curved path having a shape corresponding to. the shape ofthe face of the workpiece whereby'the grinding means moves alongthe face during movement of the supporting means, operating means for moving the supporting means on the guiding means along the path, and means for oscillating one of the above'mentioned means so that the grinding means, oscillates on the face of the workpiece. g n

According to a preferred embodimentQthe grinding machine of the present invention comprises a machine base, a turnable supporting member turnably mounted on the machine base for turning movement about an axis, a support mounted on the machine base and adapted -tosupport a cutter having a face including two straight 2,873,557 Patented Feb. 17, 1959 face portions and a curved face portion connecting the straight face portions and having a center of curvature adapted to be arranged in the axis, a supporting arm mounted on the turnable member, first slide means mounted on the supporting arm for rectilinear movement in a direction transverse to the direction of the axis, second slide means mounted on the first slide means for oscillating movement, grinding means supported on the second slide means and adapted to engage the face of the cutter and to move along the straight face portions during movement of the first slide means and to move along the curved face portion of the cutter during turning of the turnable supporting member about the axis while oscillating with the second slide means, first operating means for moving the first slide means, second operating means for oscillatingthe second slide means on the first slide means at a speed higher than the speed of movement of the first slide means, and third operating means for turning the turnable supporting member.

Preferably, the cutter support and the supporting arm are adjustable to assume a position in which the center of curvature of the curved face portion of the cutter is located in the axis of the turnable member.

According to a preferred embodiment of the present invention, a turnable element is mounted on the supporting arm for turning movement about another axis extending perpendicular to the axis of the turnable supporting member and supports the first slide means. Operating means are provided for turning the turnable element automatically, while the grinding means is moved along the face of the cutter. The provision of the turning element is of particular importance for grinding the cutters of a cutter head in which the cutters are arranged inclined with respect to the axis of the cutter head and to radial planes, since otherwise a cutter face including two face portions extending at an angle to each other could not be ground. Turning of the grinding means by the turnable element is particularly advantageous if the two straight portions of the-cutter face define different angles with the plane of symmetry of the cutter since in this event it is necessary to turn the ground face when the grinding wheel has passed around the curved face portion of the cutter so that the grinding wheel is at the end of the adjustment in a position for grinding the other straight face portion.

It is advantageous to mount the supporting arm on the turnable member movable in radial direction with respect to the turning axis of the turnable member, and to provide a stop finger extending in the axis of the turnable, member and engaging and holding the cutter during the grinding operation. v

The novel features. which are considered as character istic for the invention are set forth, in particular in the appended claims. The invention itself, however, both as to its construction audits method of operation, to.- gether with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

Fig.' l is a side view of a grinding machine according .to the present invention;

Fig. 2 is a front view of the grinding machine;

Fig. 3 is a plan view, partly in section, of the grinding machine; a

Fig. 4 is a fragmentary sectional View through the support for a cutter head; i a

n Fig. 5 is a fragmentary sectional view through operating means for the turnable supporting member;

. Fig. 6,is a side view showing the supporting means of the grinding means; i

Fig. 7, is ,a front view, partly in section, of the slide means shown in Fig. 6;

Fig. .8 is an isometric view of a cutter;

Fig. 9 is a front view of another cutter;

Fig. is a front view of a further cutter;

Fig. 11 is a fragmentary view illustrating the arrangement of the cutting edges of a cutter as shown in Fig. 8;

Fig. 12 is a sectional View through the stop finger which engages the'cutter during the grinding operation, this section being taken along line 1212 in Fig. 1; and

Figs. 13 and 14, respectively, show the hydraulic arrangement for controlling the movements of the machine.

Referring now to the drawings and more particularly to Figs. 1, 2 and 3, the grinding machine according to the present invention comprises a base 1, a support 2 for supporting a cutter head 20, an upright support 3 forming part of themachine base, a projecting arm 4, slide means 5, and further slide means 6 for supporting the grinding means"66, 65. The lower portion of the machine base includes a container body 16 provided with legs 101. In the interior of the body 10 is arranged a hydraulic pump 11 which is driven through a shaft 13 and a coupling means 131 from an electric motor 12 which is supported on the rear wall 'of the body 10. The lower portion of the interior of container body 10 serves as a container for the operating oil 14 which forms an oil sump into which the suction pipe 111 of the pump 11 projects. At the front portion of body 10 is arranged the control panel 15 which includes a number of control means, not illustrated, for actuating the respective operating means of the machine.

The support 2, best seen in Fig. 4, includes a saddle 24 and a top slide 22 movably mounted on the saddle 24. A bearing body 21 is mounted in a flange 223 of the top slide 22. An adjusting nut means 23 is provided with handles 231 and serves for adjusting the bearing body 21 in vertical direction. The top slide 22 is mounted in guide ways of the saddle 24 by means of prismatic guides 221 and can be adjusted by means of a hand wheel 222 in the guide ways of saddle 24. Saddle 24 is mounted in the body 10 by means of prismatic guides 241 and can be adjusted by hand wheels 242 which are arranged on the side of the machine as best seen in Figs. 2 and 3.

The bearing body 21, see Fig. 2, has a substantially cylindrical shape and is provided at its upper end with an outer thread. Turning of the nut 23, which engages with its bottom face 232 a corresponding face of the top slide 22, results in vertical adjustment of the bearing body 21 and thereby of the cutter head with the cutters 27.

, A screw 224 engaging a longitudinal groove 212 in the bearing body 21 prevents turning of thebody 21.. The cutter head 20 is secured to the frusto-conical shaft 213 by a threaded pin and a nut. Shaft 213 is turnable in a corresponding conical recess of the bearing body 21, and has at its lower end a recess engaged by the shaft end 251 of a hydraulic engine 25. The shaft 213 is taken along by the key 252 when the hydraulic engine 25 rotates. The hydraulic engine 25 is secured by a flange 253 and screws 254 to the bearing body 21 and has supply and discharge conduits which are not'illustrated in the drawing for the sake of clarity.

Turning of the cutter head 20 is prevented during the grinding operation by a stop finger 26 which is secured to the upright portion 3 of the machine base. During the by automatic control means so that the cutter head 20 rotates man opposite direction until the next following cutter 27 engages the stop finger 26 intheinitial position of the same whereby further movement of the cutter and of the cutter head is blocked, and the cutter is arrested in grinding position. The automatic control means are disclosed in my co-pending application, Serial No. 505,423, filed May 2, 1955.

A shaft 30 is turnably mounted on ball bearings 40 in the upright portion 3 of the machine base. A face plate 31 is fixedly connected to the shaft 30, as best seen in Fig. 3. A guiding ring 41 guides the outer rim of the face plate 31 and is secured to the upright 3. The stop finger 26 is secured to a pin 33 by means of a coupling sleeve 32, and these members are arranged in such manner that the abutting point 261 of the stop finger 26 is located in the axis 34 of the face plate 31. The abutting point 261 engages the cutter 27 and serves as a point of reference for adjusting the cutters and the grinding wheel with respect to the cutter head 20. A manually operated member 35 is provided for adjusting the position of the stop finger 26 and is connected to the same by means which are best shown in Fig. 12.

As shown in Fig. 12, a spindle 109 is fixedly attached to the hub of the hand wheel 3'5. The threaded end of spindle 100 cooperates with an inner thread provided in a bore in the enlarged end of the pin 33. Axial movement of the spindle during the rotation thereof is prevented by a flange 101 attached to the spindle. A pin 102 fixed to the slide 103 and engaging in a longitudinal groove formed in the enlarged end of the pin 33 prevents turning of pin 33 during the movement thereof in longitudinal direction. The slide 103 is fastened to the support 36. Turning of the hand wheel will, therefore, shift the finger 26 in axial direction.

As best seen in Figs. 2 and 3, the guide ring 41 is provided on its outer periphery with a large gear crown 411 with which a gear 39 meshes. The small gear 39 is mounted on the face plate 31 and turns with the same so that during rotation of the face plate 31, the gear 39 rolls on the stationary gear 411 and is thereby rotated. The action of gear 39 will be explained in more detail hereinafter. V

The face plate 31 is turned by operating means comprising pistons 42 which are movably mounted in cylinders 43, as best seen in Fig. 5. The pistons 42 are reciprocated by means of the hydraulic pump 11 which pumps operating fluid through conduits, schematically shown in 'Fig. 13, into the cylinders 43.

As shown in Fig. 13, a hand-operated slide valve 1' is provided by means of which the conduits s and t can be respectively connected to the pump 11 or to the lower part of the housing 10 containing the operating oil 14. The ends of the conduits s and t distant from the slide valve r are respectively connected to the cylinders 43. If the valve r is'in the position as shownin Fig. 13 and the pump 11 is operated, oil under pressure will be furnished through the conduit t'into the left cylinder'43, as viewed in Fig. 13, .and the piston 42 located in this cylinder will be raised so as to tum thereby the gear 44 in clockwise direction, which in turn causes turning of thememb'er 31 connected to the gear 44 and tilting of the arm 47 and the grinding wheel 66 connected thereto about the axis ofthejgear 44. At the same time the fluid located under the right piston 42,as viewed in Fig. 13, is connected to the pump sump 'on the bottom of the container 10 so, that'the right piston may move downwardly while the left piston moves in upward direction. During this movement of the pistons 42 the grinding face of the grinding wheel 66'describes a curved path to grind the curved surfacelof'the cutter 27, as will be described in detail later on. r

The pistons 42 are provided on opposite faces with rack portions 421 which mesh with a gear 44 which is fixedly secured to the shaft 30. Upward movement of the pistons 42 is limitedby dogs '45 which are secured tothreaded spindles 46 and move with the same when i thespindleis turned hand :wheels 461, shafts 462,

bevel gears 463, shaft 464, and bevel gears 465. The dogs 45 and thereby the distance through which the pistons 42 move can be adjusted during operation of the grinding machine. Each piston 42 turns the face plate 31 in one direction of rotation through an angle determined by the position of the dogs 45, while the other piston 42 idles.

A member 4 is secured to a face plate 31 and carries the slide means and all adjustable supports required for adjusting the position of the grinding means. When the face plate 31 is turned the supporting arm 4 turns with the same. The member 4 includes a portion 311 which is fixedly secured to the face plate 31 and turns with the same about the axis of shaft 30. Members 30, 31, 311 constitute a turnable supporting means. The portion 311 is provided with guide ways extending in radial direction with respect to the axis of the shaft 30, and a supporting arm 47 is movable in the radially extending guide way by adjusting means which comprise a hydraulic servo-motor means including a piston 76 movable in a cylinder 761. The stroke of the piston 76 can be adjusted by the screw 762, while a spring 763 urges the 'pistoninto one of its end positions, as best seen in Fig. 2.. The piston 76 carries a pawl 77 on an extension 764. thereof. Pawl 77 cooperates with a ratchet wheel 78 which turns a shaft 781 carrying a worm 782, cooperating with a worm wheel 79 which is fixed to a shaft mounted in .a bracket 801. The end portion 802 of the shaft 80 is threaded and cooperates with a nut 81 which is fixedly connected to the face plate 31 so that the supporting arm 47 moves when shaft 80 is turned. The adjustment of the movable arm 47 can also be carried out by means of the hand wheel 783 which is fixedly connected to the shaft 781.

A turnable element 48 is turnably mounted in the slide means 47 and extends in the illustrated embodiment of the present invention in vertical direction. The turnable element 48 includes a flange 481. by which it is secured to the supporting arm 47. A hand wheel 49 is provided for operating the turnableelement 48 through a shaft 491 and a worm .492 which meshes with a worm Wheel 482 rigidly secured to the pin 48. The shaft 491 is slidably mounted in a bore of the worm 492. The turnable element 48 is driven through transmission means from the face plate 31 when the same is turned.

When the turnable member 30, 31, 311, is turned the stationary. gear crown 411 efiects rotation of the gear 39 which rolls on the same while moving with face plate 31. Shaft 38 connected to gear 39, transmits the turning movement through a universal joint shaft 381 to the shaft 382 which carries worm 383, see Fig. 2. Worm 383 meshes with a worm gear 701 which is fixedly secured to the bushing 70. "Bushing 70 is provided with an eccentric bore'in which a bolt 71 is arranged with its eccentricpin 711 (Fig. 3'). By means of a nut which engages a threaded end portion of the bolt 71, the shoulder 712 of bolt 71 is pressed against the bushing 70for clamping the bolt. The pin 711 of the bolt 71 engages a'groove in a member 73 which is mounted on a shaft 74. When pin 711 is turned, the member 73 moves the shaft 74 in axial direction, see Fig. 3. 'The worm 492 is fixed to the shaft 74, and

turns the turnable element 48 when shaft 74' is axiallyshifted. The shaft 491 of the hand wheel 49 projects into an axialrecess in the shaft 74 so that shifting of shaft 74 ispossible.

The turnable element 48 is fixedly connected with a saddle 50 of a slide and has a smooth top surface sliding during turning on a corresponding face of the projecting. arm 47. The bottom face of saddle 50 is provided with guide ways 501- in which a first slide means is guided by guide prisms 511 on balls 52, see Figs. 6fand 7. The slide 51 is operated by a hydraulic piston .53 which is movable in a corresponding cylinder 531 closed by end plates 532. A catch 54 having a 6 piston 541 is located ina bore coaxial with the turning axis of the turnable element 48 and is urged by spring 542 into a position in which the point 543 of the catch 54 engages a corresponding annular recess in the piston 53 for arresting the same and thereby the slide 51 in a center position and operating fluid can be provided in the space underneath the piston 541 to lift the point 543 out of engagement with the annular groove.

The slide 51 is provided at its lower portion with an arcuate guideway 512 which is arranged in such manher that the axis of the corresponding cylinder passes substantially through the abutment point 261 of the stop finger 26. The holding means 6 of the grinding means 65, 66 can be moved along this arcuate guideway which has preferably the shape of a portion of a circle. This movement is produced by a manually operated member 55 connected to the holding means 6 by shaft 551 and link 552. The holding means 6 is provided with several movable parts which will now be described in detail with reference to Figs. 6 and 7.

A guide means 56 is providedwith guideways 561 in which a second slide 57 having prismatic guides 571 is slidable on balls 572 in a rectilinear motion. This motion serves for moving the grinding means in an oscillating movement over the work piece. Inthe illustrated embodiment, the motion of slide means 57 is parallel to the motion of the slide 51. A second hydraulic operating means including a cylinder 59 and a piston 58 whose stroke is adjustable bymeans of an adjusting screw 581, serves for oscillating the slide means 57.

This second hydraulic operating means is shown in Figs. 13 and 14. The slide valve 1 (Fig. 13) is adapted to connect the conduits g and h, respectively, either to the pump 11 or to the pump sump 14. As shown in Fig. 14, the conduits g and h are connected to a reversing valve k which is located in the guide means 56. The reversing valve k is controlled by two rings 1 and m gfixedly mounted spaced from each other on the piston rod extending from the piston 58. If the valves f and k are in the positions as respectively shown in the Figs. 13 and 14, fluid under pressure will flow from the pump 11 through the conduit h and from there to the chamber 0 of the cylinder 59, so that the piston 58 will move to the left as viewed in Fig. 14. This will bring the arm 2 of the valve k in contact with the ring In which will, upon further movement of the piston 58, cause turning of the valve k so that the valve is reversed and the conduit it will be connected to the cylindrical chamber q causing thereby movement of the piston 58 toward the right as viewed in Fig. 14. This in turn will bring the arm 1 of the valve k in contact with the ring I, so that the. valve k is again reversed and the cycle repeated.

In this way an oscillating movement of the grinding wheel 66 is produced during the feed movement of the same.

A turning support 62 is arranged on the slide means 57 turnable about a pin 622 and can be secured in any position by means of a screw 68. On the bottom face of the turning disc 62, guide ledges 621 are arranged in which corresponding guides 601 of a carriage 60 are slidably arranged. Carriage 60 canbe arrested by screws 61 engaging the guides 601. Two brackets 64 are fixed to the carriage 60, and a drive motor 65 is turnably mounted in the brackets 64. Flexible connections 651, 652 are connected to the motor. A shaft 653 is driven by motor 65 and carries the grinding wheel 66 which is secured by attaching means 67. Members 51, 56, 57,60, 64 constitute movable supporting means for the grinding means 65, 66.

The grinding machine. according to the present invention is mainlyused for grinding the cutters of cutter heads which generally havethe shape of the cutter shown in Figs. 8 and 11. The cutter 27 has two straight cutting edgesa and c which extend at an angle to each "7 other and a curved connecting edge '12. The corresponding clearance face which is inclined at the face relief angle to the cutting face of the cutter, is composed of two straight face portions A and C, and a connecting curved face portion B.

For grinding the cutter 27 along the clearance face A, B, C it is necessary that the grinding wheel moves first along one of the straight faces A, C in a straight rectilinear motion, then moves around the curved face portion B and then continues along the other of the straight face portions A, C in a straight rectilinear movement. i

For grinding the partly curved face A, B, C of a cutter 27, the cutter head is placed in a position in which the center of curvature of the curved face portion B is substantially located in the axis of the turnable supporting member 31, 30. The turnable supporting member 31, 30, 311 is turned by the operating means 42, 44 until the arm 47 assumes a position in which the guideways 511 of the member 50 extend parallel to the face portion A. When the first slide 51 is now moved by operating means 53, the grinding wheel 66 moves along the face portion A. At the same time the second slide means 57 is oscillated by the operating means 58, 59 at a higher speed so thatthe grinding wheel 66 simultaneously oscillates and moves along the straight face portion A. The machine 'is so adjusted, that the catch 54. engages annular recess in piston 53 when the grinding wheel arrives at the point in which the straight edge a merges into the curved edge portion b. The motion of slide 51 is thereby stopped. The movement of the catch 54 is controlled from the turning movement of the ;p1ate' 31. At the beginning of the turning movement of the plate 31, the fluid, located in the space underneath thepiston 541 connected-to the catch 54, is released so that the pointed end 543 of catch 54 is pressed under the influence of the force of the spring 542 into the annular recess provided in the piston 53. At the end of the turning movement of the plate 31 operating fluid is again supplied to the space underneath the piston 541 so that the piston 541 and the catch member 54 connected thereto is raised out of the annular recess against theaction of the spring 542.

, The turnable supporting member 31, 30, 311 and more particularly the face plate 31 is now turned by the operating means 42, 43, 44 so that the grinding wheel 66 moves along the curved face portion B. The oscillating motion of thesecond slide means 57 is continued during such'movement. When the grinding wheel 66 reaches the point at which the curved edge b merges into the straight edge c, the turning movement of the turnable supporting member 30, 31, 311 is stopped, and the hydraulicmotor 53, 531' again-operated so that the piston 53 is' released by the catch 54 and continues its movement. Consequently, the first slide means 51 move along the face portion C, while the oscillating second slide means 57 continues its oscillating movement.

In the position illustrated in the drawing the oscillating movement takes place in the same direction as the main movement of the grinding Wheel which is produced,

by the slide51 and by the turnable supporting member 31, 30. However, when the guideways of member 57 are arranged transverse to the guideways of member 50, the second slide means 57 will perform an oscillating movement transverse to the motion of the first slide means 57. It will be understood that the main motion of the grinding means effected by the first slide means 51 and by the turnable supporting member 30, 31 is repeated until the cutting edges a, b, c are perfectly ground. However, the frequency of oscillation of the grinding means due to the motion of the second slide means 57 is a multiple of the frequency of the passages of the grinding means along the face A, B, C,

In some cases in which the straight face portions A and C of a cutter are very short, it is not necessary to make use of the first slide 51 for moving the grinding wheel along the face portions A, C, since an oscillating motion produced by the second slide means 51 is sufiicient to grind the face portions A and C. In this event the supporting turnable member 30, 31 is used, as previously described, for moving the grinding wheel around the curved face portion B.

From the above description of the operation of the grinding machine according to the present invention it will be understood that the members 50, 47, 311, 31 and 3t) constitute guide means for guiding the supporting means 51, 56, 57, 6t), 64 of the grinding means along a path having a shape corresponding to the shape of the face of the work piece which is to be ground. The by draulic motors 42, 43 and 531, 53 constitute'operating means for moving the movable supporting means 51, 56, 57, 60, 64 of the grinding means 65, 66 along the path defined by the guiding means. In the illustrated embodi ment, the movable supporting means support the grinding means for oscillating movement together with the second slide 57. V

In the above description of a grinding operation it has been assumed that the cutter 27 is arranged with its cutting face parallel to the axis of the cutter head 20 and extend in radial direction to the axis thereof. However, in most cutter heads the cutters are arranged inclined to the axis so that it is necessary to turn the axis of the grinding wheel 66 while it swings around the curved face portion B. This turning motion is produced 'by the turnable element 48 which is automatically operated through the gear means 41, 39, and adjusted by the eccentric pin 711. The turning about the axis of the turnable element 48 is automatically carried out since the operating transmission means 39, 38, 71, 711, 74, 492 and 482 are driven when the face plate 31 is operated by operating means 42, 43. The first slide means 51 is. arrested by catch 54 during turning movement of element 48, which is possible since catch 54 is arranged in the axis of element 48.

The grinding wheel 66 can be placed in any desired position by turning of the face plate 31, by turning of the turnable element 48, by swinging about the guide 512, by turning of the turnable disc 62, by straight motion of, the slide 66, and by turning. in thebrackets 64. Consequently, grinding wheels of all kinds including dished grinding wheels can be used in the machine. It is also possible to arrange the grinding Wheel with its main plane in the direction of the cutting edges of the cutter. i

, By adjusting the position of the grinding wheel 66 Wlthl'fiSPBCi to the abutment point 261 of the stop finger 26it is possible to grind curved cutting edges and curved face portions having different radii of curvature. Such adjustment can be carried out by moving the arm 47 in a radial direction in the guide-means 311.

Fig. 9 illustrates a cutter having a circular cutting edge which is ground by swinging the arm 47 together with the turnable supporting member-30,' 31 without making use of the slide 51. However, it is also possible to grind a cutter having the shape illustrated in Fig. 10 by adjusting the arm 47 to assume a position in which the grinding edge of the grinding wheel 66 is located in the axis of the turnable supporting member 30, 31 so that the slide means 51 produces the straight faceportlons, and the turning of the turnable supporting member 35 31 is only used for changing the direction of movement of the slide means 51. I V v Preferably, the machine according to the present. invention also includes adressing device for the grinding wheel. The upright 3 is provided ,Witlra bore into which a member is inserted. Member 90 supports' an arm 91 fat'9tl1 which is hinged at 92 to an arm. 93 which, is pivotallyconnected by a joint 94 to an arm 95.: The

and dressed during operation.

It will be understood that each of the elements described above, or two or more together, may also find auseful application in other types of grinding machines differing from the types describedaboveh While the invention has been illustrated and described as embodied in a grinding. machine for grinding an at least partly curved face and including means for guiding a grinding wheel to move along a curved path and means for oscillating the grinding wheel during movement along the path, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

, Without further analysis, the foregoing will so fully reveal the gist of the present inventionthat others can by applying current knowledge readily adapt it for vari- Ous applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics' of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is: r

1. Ina grinding machine, in combination, a machine base; a turnable supporting member turnablylm ounted on said machine base for turning movement jabout an axis; a support mounted on said machine base and adapted, to supporta cutter having a face including two straight face portions and a curved faceportion connecting said straight face portions and having a center of curvaturejadapted to be"arranged in said axis; a,supporting arm ,mountedon said-turnable member movable in :radial direction with respect to said axistfirst slide means mounted onqsaid supporting armpforre'ctilinear movement in a direction transverseto the direction of said axis; second slide means mounted onjsaid, first slide means for oscillating movement in the direction of movement of said first slide means; grinding means supported on said second slide means and adapted to engage said face of the cutter and to move along said straight face portionsduring movement of said first slide means and to movejalong said curved face portion of the cutter during turning of said turnable supporting member about said axis'whilel oscillating with saidsecond slide means; adjusting means for adjusting. the position of saidsupportingarrn' 'onj said turnable member; firstoperating means for moving said first slide means; second operating means for oscillating said second slide means on;

said first slide me'ansat a speed higher than the speed of movement of said first slide means; and third operating means for turning said turnable supporting member.

2. In a grinding machine, in combination, a machine base;r,a turnable supporting member turnably mounted on said machine baseifor turning movement about an axis; a support movably mounted on said machine base and adapted to support iacutter having a face including two straight face portions and a curved face portion connecting said straight face portions and having a center of curvature; means for adjusting the position of said supporton saidmachine base y a supporting arm mounted on said: turnable member; first slidefmeans mounted on said supporting arm for rectilinear movement in a direction transverse to the direction of said -axis; second slide rnearis fmounted on said first slideme ans for oscillating movement in the direction of movement of said first jslide means; grinding ine'anssu poned on said second slide" ingsaid straight face portions and'having a center of t t 10- means and adapted -to engage said face of the cutter and to move along said straight face portions during movement of said first slide means and to move along said curved face portion of the cutter during turning of said turnable supporting member about said axis while oscillating with said second slide means; first operating means for moving said first slide means; second operating means for oscillating said second slide means on said first slide means at a speed higher than the speed of movement of said first slide means; and third operating means for turning s aid turnable supporting member.

3. In a grinding machine, in combination, a machine base; a turnable supporting member turnably mounted on said machine base for turning movement about an axis; a support movably mounted on said machine base and adapted to support a cutter having a face including two straight face portions and a curved face portion connecting said straight face portions and having a center of curvature; means for adjusting the position of said supporton said machine base; a supporting arm mounted on said turnable member movable in radial direction with respect to said axis; first slide means mounted on said supporting arm for rectilinear movement in a direction transverse to the direction of said axis second slide means mounted on said first slide means for oscillating movement in the direction of movement of said first slide means; grinding means supported on saidsecond slidemeans and adapted to engage said face of the cutter and to move along said straight'face portions duringmovement of said first slide means and to move along said curved face portion of the cutter during turning ofjsaid turnable supporting member about said axis whileoscillating with said second slide means;

adjusting meansfor adjusting the position of said supporting arm on said turnable member; first operating means fornmoving said first slide means; second operating means for, oscillating said second slide means on saidfirs't slidemeans at a speed higher than the speed of movement of said first slide means; and third operating means forturning said turnable supporting member. f4 In a grinding machine, in combination, a machine base; a turnable supporting member turnably mounted on said machine base for turning movement about an axis; a support mountedon said machine base and adapted to support a cutter having a face including two straight face portions and a curved face portion connectcurvature adapted to be arranged in said axis; a supporting .arm mounted onsaid turnable member; a turnable element mounted on said supporting arm for turning movement about another'axis extending-perpendicular to said axis of said turnable supporting; member; first slide means mountedon said turnable element for rectilinear movement in a direction transverse to the direction of said axis; second slide means mounted on said first xslide means for oscillating movement in the direction of movement of said first slide means; grinding rriea'n'sstipported on saidhsecondj slide means and adapted to, engage said face of the cutter; and to move along said straight-face, portions during movement of said first slide means and to move along said curved face portion ofthe, cutter during turning of said turnable supporting member about said axiswhile oscillating with said second slide means; first operating means for moving said first slide means; second operating means for oscillating said I second slide means on said first slide means at a speed higher than the speed of -movement of said first slide means; third operating means for turning said turnable supportingjmember; and fourth operating means connected to ,said turnable element and driven from said third operating means for turning said turnable element. 5.' Inagrinding machine, in combination, a machine base; a turnable support member turnably mounted on saiddrnacbi ne base for turning movement about an axis; a support mounted on said machine base and adapted to support a cutter having a face including two straight face portions and a curved face portion connecting said straight face portions and having a center of curvature adapted to be arranged in said axis; a supporting arm mounted on said turnable member; a turnable element mounted on said supporting arm for turning movement about another axis extending perpendicular to said axis of said turnable supporting member; first slide means mounted on said turnable element for rectilinear movement in a direction transverse to the direction of said axis; catch means located in the axis of said turnable element and engaging and arresting said first slide means in an intermediate position of the same; second slide means mounted on said first slide means for oscillating movement in the direction of movement of said first slide means; grinding means supported on said second slide means and adapted to engage said face of the cutter and to move along said straight face portions during movement of said first slide means and to move along said curved face portion of the cutter during turning of said turnable supporting member about said axis while oscillating with said second slide means; first operating means for moving said first slide means; second operating means for oscillating said second slide means on said first slide means at a speed higher than the speed of movement of said first slide means; third operating means for turning said turnable supporting member; and fourth operating means connected to said turnable element and driven from said third operating means for turning said turnable element.

6; In a grinding machine, in combination, a machine base; a turnable supporting member turnably mounted on said machine base for turning movement about an axis; a support mounted on said machine base and adapted to support a cutter having a face including two straight face portions and a curved face portion connecting said straight face portions and having a center of curvature adapted to be arranged in said axis; a supporting arm mounted on said turnable'member movable in radial direction with respect to said axis; a turnable element mounted on said supporting arm for turning movement about another axis extending perpendicular to said axis of said turnable supporting member; first slide means mounted on said turnable element for rectilinear movement in a direction transverse to the direction of said axis; catch means located in the axis of said turnable element and engaging and arresting said first slide means in an intermediate position of the same; second slide means mounted on said first slide means for oscillating movement in the direction of movement of said first slide means; grinding means supported on said second slide means and adapted to engage said face of the cutter and to move along said straight face portions during movement of said first slide means and to move along said curved face portion of the cutter during turning of said turnable supporting member about said' axis while oscillating with said second slide means; adjusting means for adjusting the position of said supporting arm on said turnable member; first operating means for moving. said first slide means; second operating means for oscillating said second slide means on said first slide means at a speed higher than the speed of movement of said firstslidermeans; third operating means for turning said turnable supporting member; and fourth operating means connected to said turnable element and driven from said third operating means for turning said turnable element.

7 7.In a grinding machine, in combination, a machine base; a turnable supporting member turnably mounted on said machine base for turning movement about an axis; a support mounted on said machine base and adapted to support arcutter having a face including two straight face portions and a curved face portion connecting said straight face portions and having a center of curvature adapted to be arranged in said axis; a supporting arm mounted on said turnable member; first slide means mounted on said supporting arm for rectilinear movement in a direction transverse to the'direction of said axis; second slide means mounted on said first slide means for oscillating movement in the direction of movement of said first slide means; a turnable support mounted on said second slide means for turning movement about an axis extending perpendicular to the direction of oscillating movement of said second slide means; rotary grinding means supported'on said turnable support and adapt ed to engage said face of the cutter and to move along said straightface portions during movement of said first slide means and to move along said curved face portion of the cutter during turning of said turnable supporting member about said axis while oscillating with said second slide means; first operating means for moving said first slide means; second operating means for oscillating said second slide means on said first slide means at a speed higher than the speed of movement of said first slide means; and third operating means for turning said turnable supporting member.

8. In a grinding machine, in combination, a machine base; a turnable supporting member turnably mounted on said machine base for turning movement about an axis; a support mounted on said machine base and adapted to support a cutter having a face including two straight face portions and a curved face portion connecting said straight face portions and having a center of curvature adapted to be arranged in said axis; a supporting arm mounted on said turnable member; first slide means mounted on said supporting arm for rectilinear movement in a direction transverse to the direction of said axis; second slide means mounted on said first slide means for oscillating movement in the direction of movement of said first slide means; a turnable support mounted on said second slide means for turning movement about an axis extending perpendicular to the direction of oscillating movement of said second slide means and including a carriage movable in a direction transverse to the direction of oscillating movement of said second slide means; rotary grinding means supported on said carriage and adapted to'engage said face of the cutter and to move along said straight face portions during movement of said first slide means and to move along said curved face portion of the cutter during turning of said turnable supporting member about said axis while oscillating with said-second slide means; first operating means for moving said first slide means; second operating means for oscillating said second slide means on said first slide means at a speed higher than the speed of movement of said first slide means; and third operating means for turning said turnable supporting member.

I 9. A grinding machine as claimed in claim 8 wherein said turnable support and thereby said grinding means is turnable through at least and wherein said rotary grinding means has an axis extending in the direction of movement of said carriage.

10. In a grinding machine, in combination, a machine base; a turnable supporting member turnably mounted on said machine base for turning movement about an axis; a support mounted on said machine base and adapted to support a cutter having a face including two straight face portions and a curved face portion connecting said straight face portions and having a center of curvature adapted to be arranged in said axis; a supporting arm mounted on said turnable member movablein radial direction with respect to said axis; a turnable ele-,

ment mounted on said supporting arm for turning movement about another axis extending perpendicular to said axis of said turnable supporting member; first slide means mounted on said turnable element for rectilinear movement in a direction transverse to the direction of said axis; catch means located in the axis of said turnable element and engaging and arresting said first slide means in aninte'rmediate position of the same; second slidefmeans mounted on said first slide means for Oscillating movement in the direction of movement of said first slide means; a turnable support mounted on said second slide means for turning movement about an axis extending perpendicular to the direction of oscillating movement of said second slide means and including a carriage movable in a direction transverse to the, direction of -oscillating movement of saidsecond slide means; rotary grinding means supported on said carriage and adapted to engage said face of the cutter andto move along said straight face portions during movement of said first slide means and to move along said curved face portion of the cutter during turning of said turnable supporting member about said axis while oscillating with said second slide means; adjusting means for adjusting the position of said supporting arm on said turnable member; first operating means for moving said first slide means; second operating means'for oscillating said, second slide means on said first slide means at a speed higher'than the speed of movement of said first slide means; third operating means for turning said turnable supporting member; and fourth operating means connected to said turnable element and driven from said third operating means for turning said turnable element.

11. In a grinding machine, in combination, a machine base; a turnable supporting member mounted on said machine base for turning movement about an axis; a support mounted on said machine base and adapted to support a cutter having a face including two straight face portions and a curved face portion connecting said straight face portions and having a center of curvature adapted to be arranged in said axis; a supporting arm mounted on said turnable member; first slide means mounted on said supporting arm for rectilinear movement in a direction transverse to the direction of said axis; a second slide means mounted on said first slide means for oscillating movement in the direction of movement of said first slide means; grinding means supported on said second slide means and adapted to engage said face of the cutter and to move along said straight face portions during movement of the said first slide means and to move along said curved face portion of the cutter during turning of said turnable supporting member about said axis while oscillating with said second slide means; first operating means for moving said first slide means; second operating means for oscillating said second slide means on said first slide means at a speed higher than the speed of movement of said first slide means; and third operating means for turning said turnable supporting member.

12. In a grinding machine, in combination, a machine base; a turnable supporting member turnably mounted on said machine base for turning movement about an axis; a support mounted on said machine base and adapted to support a cutter having a face including two straight face portions and a curved face portion connecting said straight face portions and having a center of curvature adapted to be arranged in said axis; a supporting arm mounted on said turnable member; a turnable element mounted on said supporting arm for turning movement about another axis extending perpendicular to said axis of said turnable supporting member; first slide means mounted on said turnable element for rectilinear movement in a direction transverse to the direction of said axis; second slide means mounted on said first slide means for oscillating movement; grinding means supported on said second slide means and adapted to engage said face of the cutter and to move along said straight face portions during movement of said first slide means and to move along said curved face portion of the cutter during turning of said turnable supporting member about said axis while oscillating with said second slide means; first operating means for moving said first slide means; second operating means for oscillating said second slide means on said first slide; transmission means connecting said turnable element with said turnable supporting member so that said turnable element turns with said turnable supporting member at a reduced rotary speed; and third operating means for turning said turnable supporting member and thereby said turnable element. a

13. A grinding machine as claimed in claim 12 wherein said transmission means includes a large gear coaxial with said turnable supporting member and fixed on said machine base; a small gear turnably mounted on said turnable supporting member and meshing with said large gear so as to roll on the same during turning of said turnable supporting member; worm gear means connected to said turnable element for turning the same; and means connecting said small gear with said worm gear means.

14. In a grinding machine, in combination, a machine base; a 'turnable supporting member turnably mounted on said machine base for turning movement about an axis; a support mountedon said machine base and adapted to support a cutter having a faceincluding two straight face portions and a curved face portion connecting said straight face portions and having a center of curvature adapted to be arranged in said axis; 'a supporting arm mounted on said turnable member movable in radial direction with respect to said axis; a turnable element mounted on said supporting arm for turning movement about another axis extending perpendicular to said axis of said turnable supporting member; first slide means mounted on said turnable element for rectilinear movement in a direction transverse to the direction of said axis; second slide means mounted on said first slide means for oscillating movement; grinding means supported on said second slide means and adapted to engage said face of the cutter and to move along said straight face portions during movement of said first slide means and to move along said curved face portion of the cutter during turning of said turnable supporting member about said axis while oscillating with said second slide means; adjusting means for adjusting the position of said supporting arm on said turnable member; first operating means for moving said first slide means; second operating means for oscillating said second slide means on said first slide; transmission means connecting said turnable element with said turnable supporting member so that said turnable element turns with said turnable supporting member at a reduced rotary speed; and third operating means for turning said turnable supporting member and thereby said turnable element.

15. In a grinding machine, in combination, a machine base; a turnable supporting member turnably mounted on said machine base for turning movement about an axis; a support mounted on said machine base and adapted to support a cutter having a face including two straight face portions and a curved face portion connecting said straight face portions and having a center of curvature adapted to be arranged in said axis; a supporting arm mounted on said turnable member movable in radial direction with respect to said axis; grinding means for grinding said face of said cutter; mounting means mounted on said'support arm and supporting said grinding means for rectilinear feed movement in a direction transverse to the direction of said axis and for oscillating movement in the same direction; adjusting means for adjusting the position of said supporting arm on said turnable member; first operating means for imparting a feed movement in said direction to said grinding means; second operating means for imparting an oscillating movement to said grinding means at a speed higher than the speed of said feed movement; and third operating means for turning said turnable supporting member, whereby said grinding means may be moved along said straight face portions of said cutter by said first operating means and be moved along said curved face portion during turning of said turnable supporting member about said axis while being oscillated by said second operating means. I

16. In a grinding machine, in combination, a machine base; a turnable supporting member turnably mounted on said machine base for turning movement about an axis; a support mounted on said machine base and adapted to support a cutter having a face including two straight face portions and a curved face portion connecting said straight face portions and having a center of curvature adapted to be arranged in said axis; a supporting arm mounted on said turnable member movable in radial direction with respect to said axis; slide means mounted on said supporting arm for rectilinear movement in a direction transverse to the direction of said axis; oscillating means mounted on said slide means for oscillating movement in the direction of movement of said slide means; grinding means operatively connected to said oscillating means and adapted to engage said face of the cutter and to move along said straight face portions during movement of said slide means and to move along said curved face portion of the cutter during turning of said turnable supporting member about said axis 16 while oscillating with said oscillating means; adjusting means for adjusting the position of said supporting arm on said turnable' member; first operating means for mov ing said slide means; second operating means for oscillating said oscillating means at a speed higher than the speed of movement of said slide means; and third operating means for turning said turnable supporting member.

References Cited in the file of this patent UNITED STATES PATENTS 1,039,075 Smi h Sept. 17, 1912 1,146,684 Bauer July 13, 1915 1,698,909 Currier Ian. 15, 1929 2,055,361 1 Oliver Sept. 22, 1936 2,108,029 Connor Feb. 8, 1938 2,751,718 Falkman et a1. June 26, 1956 FOREIGN PATENTS 612,086 7 Germany Apr. 15, 1935 618,306

Germany Sept. 5, 1935 

